1. Technical Field of the Invention
The invention relates to a reproduction apparatus for producing prints on a medium that includes a printing unit and a control unit, the control unit being required to run through a shutdown procedure prior to the switching off the control unit.
2. Description of Related Art
Digital reproduction machines are generally constructed from at least two basic units: a print unit and a control unit. The print unit, or engine, ensures that electronic image information available in the form of a bitmap is printed on an image carrier, such as paper for example. The control unit, also known as the "controller" or "front-end", has the task of converting incoming print jobs to a form suitable for the print unit, buffering them if necessary, and, at the time that the print unit indicates that it is ready for printing, sending the necessary information to the print unit.
A control unit is frequently embodied by the use of one or more hardware components such as a CPU board, a hard disk, and a network card and one or more software components, such as an operating system, drivers, and application programs.
Since a control unit must be capable of processing large quantities of information in a short time, dedicated hardware and software components have hitherto been used for the purpose. The mass production of personal computers, however, has resulted in ever-faster general purpose hardware components and general purpose operating systems becoming available.
Recently there has also been a trend to base reproduction system control units on these general purpose hardware and software components. Advantages are, on the one hand, the lower cost of these standard components in comparison with the development costs required for dedicated components and, on the other hand, the continuing development of these standard components to ever faster processing speeds, so that future reproduction machines which, as a result of trends toward higher resolution, higher production, more refined image processing and color, make ever-increasing demands of processing speed of the control unit, will still be able to use such standard components.
One property of these general purpose systems is frequently the fact that if they are switched off a shutdown procedure should be run through before the system really may be switched off in a safe and problem-free manner. The shutdown procedure terminates all the current actions of the control unit in the correct manner and so that data stored during operation of the system in different volatile memories and buffers can be written to a writable permanent memory, e.g. a hard disk in the system itself or storage unit on a server, which can be accessed via a network. In this way, the system is brought into a definite state before switching off and no data are lost.
If the system is switched off without the shutdown procedure being run through, the system becomes corrupted, which means that when the system is subsequently started it is no longer possible to find all the required data so that the system is in an error mode. A hard disk contained in the system may also be damaged if the system is repeatedly shut down without running through a shutdown procedure.
In reproduction apparatus, and particularly reproduction apparatus which is unmanned in a generally accessible area and intended for general use, it is conventional to connect such apparatus to an external timer, which switches the apparatus on and off at preset times.
In the case of reproduction apparatus equipped with a control unit having a shutdown procedure, this method of operation causes problems and inconvenience. The control unit should run through a shutdown procedure beforehand; if this is overlooked, the apparatus will be switched off without running through the shutdown procedure, with all the above-described disadvantageous consequences thereof.